> The RDFCore WG has me to forward the comments below on their behalf. Other
> comments, on behalf of RDFCore will be sent in separate messages.
>
> Brian
>
> ------------------------------
>
> owlsas-rdfcore-np-complete
>
> RDFCore notes the a consequence of the rules for owl:equivalentClass is
> that distinguishing OWL DL from OWL Full has complexity NP complete and
> suggests WEBONT investigate whether this complexity can be reduced.
This is currently being investigated. We expect that the situation will
change.
> We note from the RDF semantics document
>
> [[
> Specifications of such syntactically restricted semantic extensions MUST
> include a specification of their syntactic conditions which are sufficient
> to enable software to distinguish unambiguously those RDF graphs to which
> the extended semantic conditions apply.
> ]]
> http://www.w3.org/TR/rdf-mt/
Hmm. I'm not sure what the point of this note is.
> -------------------------------
>
> owlsas-rdfcore-bnodes-restrictions
>
> RDFCore are concerned that restrictions placed on b-nodes will limit the
> applicability of OWL DL to an unnecessarily restricted subset of RDF
> instance data, for which no such restrictions apply.
>
> For example, consider the use case in:
>
> http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2003May/0109.html
>
> [[
> If bNodes can only be used as the object of a single triple, they lose most
> of their value as a construct in the language. As does rdf:nodeID for that
> matter.
>
> <Image>
> <depicts>
> <Person>
> <mbox rdf:resource="mailto:danbri@w3.org"/>
> </Person>
> </Image>
>
> <Group>
> <member>
> <Person>
> <homepage rdf:resource="http://www.w3.org/People/DanBri/"/>
> </Person>
> </member>
> </Group>
>
> ...is OK in OWL, but if we add in an rdf:nodeID on the two Person elements
> to express that they serialize descriptions of the same (un-named) resource,
> we're in trouble? Ouch. That breaks most of my uses of RDF, and a lot of
> deployed FOAF documents.
> ]]
>
>
> Specifically we request, that in Owl DL and Owl lite:
>
> a) that a b-node representing an individual may be the object of more
> than one triple
> b) that cycles of b-nodes representing individuals be allowed.
We note that this is a restriction that until recently has also been in
RDF. It is thus hard for us to see how this can break any significant
number of deployed uses of RDF.